Due to actualization of environmental problems in recent years, hybrid cars and electric cars have spread. Further, as an air conditioner device which is applicable to such a vehicle, there has been developed an air conditioner device which includes an electric compressor to compress and discharge a refrigerant, a radiator (a condenser) disposed on a vehicle interior side to let the refrigerant radiate heat, a heat absorber (an evaporator) disposed on the vehicle interior side to let the refrigerant absorb heat, and an outdoor heat exchanger disposed outside a vehicle interior to let the refrigerant radiate or absorb heat, and which changes and executes respective operation modes of a heating mode to let the refrigerant discharged from the compressor radiate heat in the radiator and let the refrigerant by which heat has been radiated in this radiator absorb heat in the outdoor heat exchanger, a dehumidifying mode to let the refrigerant discharged from the compressor radiate heat in the radiator and let the refrigerant by which heat has been radiated in the radiator absorb heat in the heat absorber, and a cooling mode to let the refrigerant discharged from the compressor radiate heat in the outdoor heat exchanger and let the refrigerant absorb heat in the heat absorber.
Furthermore, a plurality of solenoid valves are used, and a coil of each solenoid valve is energized or non-energized to change an opened/closed state in each of the operation modes, thereby controlling the flow of the refrigerant in each operation mode (e.g., see Patent Document 1).